Anther and pollen development in garden pea and cultivated lentil

1979 ◽  
Vol 57 (18) ◽  
pp. 1883-1900 ◽  
Author(s):  
Julie A. Biddle
Keyword(s):  
Pollen Development ◽  
Developmental Stages ◽  
Light And Electron Microscopy ◽  
Generative Cell ◽  
Middle Lamella ◽  
Early Prophase ◽  
Callose Wall ◽  
Low Viscosity ◽  
Sporogenous Tissue ◽  
Mother Cells

After conventional fixation procedures and embedding in low-viscosity resin, anthers were studied using light and electron microscopy. Wall development is dicotyledonous. Sporogenous tissue undergoes one mitosis before meiosis. Entry of pollen mother cells (PMCs) into meiosis is indicated by formation of a prominent polar nucleolar cap. Cytomictic channels form between PMCs in early prophase I. In Pisum sativum the middle lamella breaks down between meiocytes. The quartets are surrounded by an extensive callose wall within which primexine starts to form. Callose dissolution is centripetal. Once microspores are released from the callose wall tectate exine development continues and the pollen cytoplasm vacuolates. Mature cytoplasm of the pollen exhibits zonation. No plastids were observed in the generative cell. Endothecial cells develop extensive thickenings. In Pisum the thickenings are primarily cellulosic whereas in Lens culinare besides cellulose some lignin may be present. Various developmental stages of the secretory tapetum have been followed. Tapetal senescence begins at about microspore mitosis. Only minor variations in anther and pollen development occur between Pisum and Lens.

scholarly journals The Study of Pollen Development in Nine Cultivars of Hazelnut (Corylusavellana)

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1117A-1117
Author(s):  
Chantalak Tiyayon ◽  
Anita Nina Azarenko
Keyword(s):  
Pollen Development ◽  
Developmental Stages ◽  
Male Gametophyte ◽  
Male Flower ◽  
Pollen Grains ◽  
Corylus Avellana ◽  
Tissue Sections ◽  
Development And Differentiation ◽  
Mother Cells ◽  
Pollen Shed

Pollen development is an important event in plant reproduction. Hazelnut (Corylus avellana) male flower differentiation starts in summer and pollen shed is in the winter. Hazelnut pollen shed can vary up to 3 months between early to late flowering genotypes. Microsporogenesis and microgametogenesis of hazelnut is not well understood. Pollen development and differentiation of nine genotypes, representing early to late blooming cultivars from the National Clonal Germplasm Repository in Corvallis, Ore., were studied. Catkins were collected weekly from Aug. to Nov. 2002. Tissue sections were examined under the light microscope. Microsporogenesis was divided into five stages: archesporial cells, sporogenous cells and parietal layers, pollen mother cells (PMC), tetrads, and microspores. Microgametogenesis was distinguished between young pollen grains (uninucleate) and mature pollen grains (binucleate). On 4 Aug., cultivars were at different developmental stages of microsporogenesis. Early blooming cultivars had PMCs present. Later-blooming cultivars only contained archesporial cells. PMCs were present in all cultivars by 22 Aug. Microspores were observed on 26 Sept. in all cultivars. This study contributes to a better understanding of male gametophyte development in hazelnut, which has increased our ability to correlate hazelnut pollen development with bloom phenology.

scholarly journals Ultrastructural studies on the sporogenous tissue and anther wall of Leucojum aestivum (amaryllidaceae) in different developmental stages

2012 ◽  
Vol 84 (4) ◽  
pp. 951-960 ◽  
Author(s):  
Nuran Ekici ◽  
Feruzan Dane
Keyword(s):  
Developmental Stages ◽  
Male Gametophyte ◽  
Anther Wall ◽  
Pollen Mother Cells ◽  
Ultrastructural Studies ◽  
Leucojum Aestivum ◽  
Sporogenous Tissue ◽  
Mother Cells ◽  
Polar Distribution ◽  
Early Phases

In this study, ultrastructures of anther wall and sporogenous tissue of Leucojum aestivum were investigated during different developmental stages. Cytomictic channels were seen between pollen mother cells during prophase I. Polar distribution was described in the organelle content of pollen mother cells and microspores in early phases of microsporogenesis and also in pollen mitosis. Active secretion was observed in tapetal cells. Previous reports about developmental stages of male gametophyte were compared with the results of this study.

Microtubular and actin filament configurations during microspore and pollen development in Brassica napus cv. Topas

1992 ◽  
Vol 70 (7) ◽  
pp. 1369-1376 ◽  
Author(s):  
G. Hause ◽  
B. Hause ◽  
A. A. M. Van Lammeren
Keyword(s):  
Brassica Napus ◽  
Pollen Development ◽  
Developmental Stages ◽  
Generative Cell ◽  
Immunofluorescent Staining ◽  
Brassica Napus L ◽  
Cell Stage ◽  
Rhodamine Phalloidin ◽  
Microtubular Cytoskeleton ◽  
Microspore Mitosis

The structures of the microtubular and microfilamental cytoskeletons were investigated during the development of microspores and pollen grains of Brassica napus L. cv. Topas. Microfilaments were observed directly with rhodamine–phalloidin and microtubules with FITC by indirect immunofluorescent staining and transmission electron microscopy. We observed microtubules in all developmental stages and noted several changes in the configuration of the microtubular cytoskeleton during microspore development, microspore mitosis, and pollen development. A preprophase band before microspore mitosis was not observed. The arrest of the microspore nucleus in an eccentric position is likely caused by microtubules as is the shape of the phragmoplast at microspore mitosis. Despite the application of various staining methods, i.e., labelling of fixed and unfixed fresh and cryosectioned microspores and pollen with rhodamine–phalloidin, microfilaments could not be observed in all developmental stages. Prominent microfilamental arrays were observed during cytokinesis of microspore mitosis and during the free generative cell stage. They mark the stages with different configurations. Key words: Brassica napus, immunolabelling, cytoskeleton, microspore and pollen development.

scholarly journals Prunus necrotic ringspot virus Early Invasion and Its Effects on Apricot Pollen Grain Performance

2007 ◽  
Vol 97 (8) ◽  
pp. 892-899 ◽  
Author(s):  
Khalid Amari ◽  
Lorenzo Burgos ◽  
Vicente Pallas ◽  
María Amelia Sanchez-Pina
Keyword(s):  
Developmental Stages ◽  
Generative Cell ◽  
Pollen Grains ◽  
Growth Zone ◽  
Pollen Tubes ◽  
Climatic Conditions ◽  
Pollen Grain ◽  
Ringspot Virus ◽  
Prunus Necrotic Ringspot Virus

The route of infection and the pattern of distribution of Prunus necrotic ringspot virus (PNRSV) in apricot pollen were studied. PNRSV was detected both within and on the surface of infected pollen grains. The virus invaded pollen during its early developmental stages, being detected in pollen mother cells. It was distributed uniformly within the cytoplasm of uni- and bicellular pollen grains and infected the generative cell. In mature pollen grains, characterized by their triangular shape, the virus was located mainly at the apertures, suggesting that PNRSV distribution follows the same pattern as the cellular components required for pollen tube germination and cell wall tube synthesis. PNRSV also was localized inside pollen tubes, especially in the growth zone. In vitro experiments demonstrated that infection with PNRSV decreases the germination percentage of pollen grains by more than half and delays the growth of pollen tubes by ≈24 h. However, although PNRSV infection affected apricot pollen grain performance during germination, the presence of the virus did not completely prevent fertilization, because the infected apricot pollen tubes, once germinated, were able to reach the apricot embryo sacs, which, in the climatic conditions of southeastern Spain, mature later than in other climates. Thus, infected pollen still could play an important role in the vertical transmission of PNRSV in apricot.

scholarly journals Autoradiographic studies of DNA and histone synthesis in successive differentiation stages of pollen grain in Hyacinthus orientalis L.

2014 ◽  
Vol 50 (3) ◽  
pp. 367-380 ◽  
Author(s):  
Elżbieta Bednarska
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Vegetative Cell ◽  
Developmental Stages ◽  
Generative Cell ◽  
Pollen Grain ◽  
Cell Nuclei ◽  
Hyacinthus Orientalis ◽  
Histone Synthesis ◽  
Generative Cells

DNA and histone synthesis in five consecutive morphological stages of <em>Hyacinthus orientalis</em> L. pollen grain differentiation were studied autoradiographically. DNA synthesis was found to occur in both the generative and the vegetative cell. DNA replication in the generative cell took place when the generative cell was still adhered to the pollen grain wall but already devoid of callose wall. DNA synthesis in the generative cell slightly preceded that in the vegetative cell. Histones were synthesized in phase S of the generative and vegetative cell. In the generative cell histone synthesis also continued at a lower level after completion of DNA replication. In the developmental stages under study the nuclei of the generative cells were decidedly richer in lysine histones than vegetative cell nuclei.

Microsporogenesis in Larix laricina

1982 ◽  
Vol 60 (6) ◽  
pp. 797-805 ◽  
Author(s):  
J. Peter Hall
Keyword(s):  
Propionic Acid ◽  
Seed Yield ◽  
Pollen Development ◽  
Abnormal Chromosome ◽  
Acid Mixture ◽  
Larix Laricina ◽  
Normal Pattern ◽  
Mother Cells ◽  
Male Strobili

Microsporogenesis was studied in Larix laricina in eastern Newfoundland at weekly intervals from October to April in four successive seasons. Male strobili were fixed in a 3:1 ethanol – propionic acid mixture, stained in alcoholic carmine, and squashed in 45% acetic acid.Pollen mother cells began development from interphase in early October and passed through leptotene, zygotene, and pachytene by mid-November. They remained in diplotene until mid-March to early April when meiosis was completed over a 2-to 4-week period. Microspores were produced by early May. The pattern of meiotic divisions, their duration, and variability within and between trees in L. laricina was similar to those reported for L. decidua, L. kaempferi, L. sibirica, and L. eurolepis.Deviation from the normal pattern occurred infrequently. In six trees the "resting diplotene" of winter was interrupted on one occasion and some male strobili had a "delayed meiosis" which occurred several days after meiosis in all other sampled strobili. Abnormal chromosome separations were observed on a few occasions; these consisted mostly of lagging chromosomes, a common abnormality in Larix meiosis. The implications for pollen development and seed yield are discussed.La microsporogénèse chez Larix laricina dans l'est de Terre-Neuve a été étudiée à intervalles hebdomadaires d'octobre à avril, pendant quatre années successives. Les strobiles mâles étaient fixés dans un mélange 3 : 1 d'éthanol – acide propionique, colorés au carmin alcoolique et écrasés dans l'acide acétique 45%.

scholarly journals snRNP: Rich Nuclear Bodies inHyacinthus orientalisL. Microspores and Developing Pollen Cells

2009 ◽  
Vol 2009 ◽  
pp. 1-12 ◽  
Author(s):  
K. Zienkiewicz ◽  
E. Bednarska
Keyword(s):  
Pollen Development ◽  
Rna Synthesis ◽  
Generative Cell ◽  
Pollen Grains ◽  
Strong Relationship ◽  
Nuclear Bodies ◽  
Cajal Body ◽  
Sm Proteins ◽  
Hyacinthus Orientalis

The aim of the present work was the characterization of nuclear bodies in the microspore and developing pollen cells ofHyacinthus orientalisL.. The combination of Ag-NOR, immunofluorescence and immunogold techniques was used in this study. The obtained results showed the presence of highly agyrophylic extranucleolar bodies in microspore and developing pollen cells, which were finally identified as Cajal bodies. In all cases, a strong accumulation of snRNP-indicating molecules including TMG cap, Sm proteins and U2 snRNA, was observed in the examined nuclear bodies. In contrast to their number the size of the identified structures did not change significantly during pollen development. In the microspore and the vegetative cell of pollen grains CBs were more numerous than in the generative cell. At later stages of pollen development, a drastic decrease in CB number was observed and, just before anthesis, a complete lack of these structures was indicated in both pollen nuclei. On the basis of these results, as well as our previous studies, we postulate a strong relationship between Cajal body numbers and the levels of RNA synthesis and splicing machinery elements in microspore and developing pollen cells.

Colleters in the vegetative axis of Aechmea blanchetiana (Bromeliaceae): anatomical, ultrastructural and functional aspects

2018 ◽  
Vol 66 (5) ◽  
pp. 379 ◽  
Author(s):  
Igor Ballego-Campos ◽  
Elder Antônio Sousa Paiva
Keyword(s):  
Developmental Stages ◽  
Light And Electron Microscopy ◽  
Secretory Activity ◽  
Functional Roles ◽  
Reproductive Axis ◽  
Functional Aspects ◽  
The Family ◽  
Marginal Cells ◽  
First Time

Colleters are common among eudicotyledons, but few records exist for monocotyledons and other groups of plants. For Bromeliaceae, mucilage secretions that protect the young portions of the plant have been observed only in the reproductive axis, and little is known about the secretory systems behind this or even other kind of secretions in the family. We aimed to describe, for the first time, the occurrence of colleters associated with the vegetative shoot of Aechmea blanchetiana (Baker) L.B.Sm., and elucidate aspects of their structure, ultrastructure and secretory activity. Samples of various portions of the stem axis were prepared according to standard methods for light and electron microscopy. Colleters were found compressed in the axillary portion of leaves and in all leaf developmental stages. Secretory activity, however, was found to be restricted to young and unexpanded leaves. The colleters displayed a flattened hand-like shape formed by a multiseriate stalk and an expanded secretory portion bearing elongated marginal cells. Ultrastructural data confirmed that the secretory role of the colleters is consistent with mucilaginous secretion. The functional roles of the colleters are discussed with regard to environmental context and intrinsic features of the plant, such as the presence of a water-impounding tank.

Autoradiography of Soluble [2-14C]Thymidine Derivatives During Meiosis And Microsporogenesis in Lilium Anthers

1967 ◽  
Vol 2 (3) ◽  
pp. 387-400 ◽  
Author(s):  
J. HESLOP-HARRISON ◽  
A. MACKENZIE
Keyword(s):  
Meiotic Prophase ◽  
Trichloroacetic Acid ◽  
Thymidine Incorporation ◽  
Callose Wall ◽  
Autoradiographic Method ◽  
Tapetal Cells ◽  
Mother Cells

A dry autoradiographic method suitable for locating soluble tracers has been used to follow the fate of [2-14C]thymidine supplied to detached buds and inflorescences of Lilium henryi and a related cultivar. During the interval from the archesporial phase until pachytene, the derivative (or derivatives) reaching the anther loculi moved freely into the meiocytes. Subsequently, the tracer was excluded from the mother cells until the dissolution of the tetrads. The young spores readily took up tracer in the thecal fluid upon their release, and yielded strongly localized autoradiographs. These observations are interpreted as indicating that access of materials to the meiocytes is related to the formation of cytoplasmic links between mother cells in the early meiotic prophase, and the later severance of these links through the growth of the isolating callose wall which comes to invest the tetrads. Judged from the tracer retained in preparations extracted with trichloroacetic acid, thymidine incorporation occurs mostly in the premeiotic and early leptotene period, although there is some slight evidence of incorporation later in prophase. In the tapetal cells, incorporation occurred in most of the stages tested, but there was no indication of a transfer of labelled materials from tapetum to spores in the post-meiotic period.

Changes in structure of the frontal filament in sequential developmental stages of Caligus elongatus von Nordmann, 1832 (Crustacea, Copepoda, Siphonostomatoida)

1993 ◽  
Vol 71 (5) ◽  
pp. 889-895 ◽  
Author(s):  
W. Piasecki ◽  
B. M. MacKinnon
Keyword(s):  
Electron Microscopy ◽  
Life Cycle ◽  
Developmental Stages ◽  
Light And Electron Microscopy ◽  
Frontal Organ ◽  
Frontal Filament

The frontal filament of larval and adult Caligus elongatus was examined using light and electron microscopy. No trace of a frontal filament was evident in eggs, nauplii, or young copepodids. The structure develops in older copepodids in a cuticular pocket in the cephalothorax. Upon infecting a fish, the filament extrudes and attaches permanently to the host. The subsequent chalimus stages inherit the filament. Before moulting, the "frontal organ" produces an extension lobe, which is attached to the old filament by each subsequent chalimus stage during the moult. The structure of the frontal filament is described and illustrated, as well as some details of the frontal organ. Some new terms are proposed for the elements of the filament and the organ. The suggestion is made that the life cycle of C. elongatus includes five, not four, chalimus stages.

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